XSS in Six Apart Ltd. Movable Type Advanced (Software Edition)
CVE-2025-54856
Movable Type contains a stored cross-site scripting vulnerability in Edit ContentData page. If crafted input is stored by an attacker with "ContentType Management" privilege, an arbitrary script may be executed on the web browser of the user who accesses Edit ContentData page.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.002 (12.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 12.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
- Six Apart Ltd. Movable Type Advanced (Software Edition) — versions 8.4.0 to 8.4.3 (8.4 series), 8.0.0 to 8.0.7 (8.0 series), 7 r.5509 and earlier (7 series)
- Six Apart Ltd. Movable Type (Cloud Edition) — versions 8.7.0 (8 series), 7 r.5509 (7 series)
- Six Apart Ltd. Movable Type Premium (Advanced Edition) (Software — versions 2.10 and earlier (2 series), 1.67 and earlier (1 series)
- Six Apart Ltd. Movable Type Premium (Cloud Edition) — versions 2.10 (2 series), 1.67 (1 series)
- Six Apart Ltd. Movable Type Premium (Software Edition) — versions 2.10 and earlier (2 series), 1.67 and earlier (1 series)
- Six Apart Ltd. Movable Type (Software Edition) — versions 8.4.0 to 8.4.3 (8.4 series), 8.0.0 to 8.0.7 (8.0 series), 7 r.5509 and earlier (7 series)
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2025-54856?
- CVE-2025-54856 is a medium-severity vulnerability in Six Apart Ltd. Movable Type Advanced (Software Edition), classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2025-10-23.
- How severe is CVE-2025-54856?
- Medium severity. CVSS v3 base score is 4.8 out of 10.